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Joint Meeting gets to work on tanks
BACK IN THE OLD ROUTINE
MULTIMODAL • THE REGULATORS ARE BEGINNING TO GET BACK INTO THE PROCESS OF MAKING NEW RULES AFTER THE COVID LOCKDOWN, STARTING WITH THE JOINT MEETING
THE SPRING 2020 session of the Joint Meeting of the RID Committee of Experts and the Working Party on the Transport of Dangerous Goods (WP 15) was an early casualty of the restrictions imposed by the spread of the Covid-19 pandemic. That meant that the experts lost their last chance to make changes to the 2021 texts of RID, ADR and ADN, the regulations that govern the transport of dangerous goods by rail, road and inland waterway, respectively, throughout Europe as well as in an increasing number of other countries.
Since then, the regulatory authorities have developed methods to enable the experts to meet in a virtual format and, in order to help them catch up, the autumn session of the Joint Meeting was extended by two days. It was held for two days in Bern on 10 and 11 September and for five days the following week in Geneva. It was chaired by Claude Pfauvadel (France) with Silvia Garcia-Wolfrum (Spain) as vice-chair. It was attended by representatives of 25 countries as full members and representatives of the European Commission, EU Agency for Railways (ERA) and 18 non-governmental organisations.
The autumn session came too late for any of the decisions it made to be included in the 2021 editions of RID, ADR and ADN so, unless adopted as corrections or addenda, will have to wait until the 2023 editions.
The Bern session was opened by Wolfgang Küpper, secretary-general of the Intergovernmental Organisation for International Carriage by Rail (OTIF), who underlined the good collaboration and the important work done by both the secretariats of OTIF and the UN Economic Commission for Europe (ECE).
TANK CONTAINER FITTINGS The session opened by discussing the progress made by the informal working group on the inspection and certification of tanks. There are three items being considered: the notification and approval of national systems for inspection bodies; the approval of Type C inspection bodies to perform periodic inspections, intermediate inspections and minor exceptional inspections; and the entry into service verification (EISV) of tanks and their reciprocal recognition. Following that discussion, the Working Group on Tanks was invited to elaborate further on these topics, taking into account the comments made, and to report back during the plenary session in Geneva.
THE JOINT MEETING IS PARTICULARLY CONCERNED
This and all other matters relating to tanks were then entrusted to the Working Group on Tanks, which met online from 10 to 16 September under the chairmanship of Arne Bale (UK), with Kees de Putter (Netherlands) acting as secretary.
The first item on the Working Group’s agenda was a proposal from OTIF to adopt new specifications for the fixing of welded elements on tank containers. This stems from discussions about the new breed of extra-large tank containers developed by BASF and Van Hool which, because of their weight when loaded, are largely moved by rail. As such, it has largely been the RID Committee of Experts’ standing working group that has considered these tanks.
In RID, 6.8.2.2.1 stipulates how welded elements are to be fixed to tank wagons in order to prevent tearing of the tank shell in the event of an accident, and the standing working group recommended that this be extended to cover tank containers; as written, this proposal covered all tank containers, not just the extra-large tanks being considered. This was despite confirmation from Van Hool and the European Chemical Industry Council (Cefic) that, in the case of extra-large tank containers, the fitting of elements to the tank wall is avoided.
The Working Group on Tanks felt that this solution would be too restrictive and, partly on the basis of an informal document from the International Tank Container Organisation (ITCO), agreed a more general wording. This was approved by plenary and will appear in the right-hand column (for tank containers) in RID and as a new second sentence in ADR under 6.8.2.2.1:
Welded elements shall be attached to the shell in such a way that tearing of the shell is prevented.
OTIF’s paper included a second proposal, to extend the 4 bar limit for manlids on tank wagons to tank containers, which was not supported. Again, this had been prompted by concerns that extra-large tank containers can experience higher levels of surge than standard tanks and there was a suggestion that it should be limited to tank containers with a capacity of more than 40,000 litres, though this again was turned down. The proposal was put back to the RID Committee of Experts for consideration at the November session of its standing working group.
TANKS FOR GASES The European Industrial Gases Association (EIGA) proposed an amendment to 6.8.3.4.6 to clarify that the first intermediate inspection of tanks intended for the carriage of refrigerated liquefied gases should be performed six years after the first periodic test; this countered a suggestion from France, that had not been able to be discussed at the September 2019 session, that the first intermediate inspection should take place three years after the initial inspection. EIGA said that the practice it proposed had been applied for many years and it did not know of any incident arising from it.
Although several experts were of the opinion that 6.8.3.4.6 only provides a derogation with regard to the periodicity of the intermediate inspection between periodic inspections, and not between the initial and first periodic inspection, it was said that it was not interpreted this way in practice. Refrigerated liquefied gases are non-corrosive and non-toxic and this would justify the longer inspection periods. There was consensus that tank containers should be treated in a similar way to tank wagons and tank vehicles and a revised 6.8.3.4.6 was adopted: For tanks intended for the carriage of refrigerated liquefied gases: (a) By derogation from the requirements of 6.8.2.4.2, the periodic inspections shall take place at least after six years at least after eight years of service and thereafter at least every 12 years. (b) By derogation from the requirements of 6.8.2.4.3, the intermediate inspections shall take place at least six years after each periodic inspection.
There is also a new transitional provision in 1.6.4.55: Tank-containers which do not comply with the requirements of 6.8.3.4.6 applicable from 1 January 2023, may continue to be used if an intermediate inspection takes place at least 6 years after each periodic inspection performed after 1 July 2023.
Poland proposed an amendment to 4.3.3.3.2 of RID/ADR which, it says, contradicts 6.8.3.5.6. The first requires that only the particulars specified in the latter shall be visible on a tank, battery-vehicle or multiple-element gas container (MEGC) when handed over for carriage; the latter requires multipurpose tanks to show the proper shipping name of all gases to whose carriage the tank is assigned. Poland noted that the provisions of »
Chapter 4.2 of RID/ADR include the applicable references to Chapter 6.7, which require the names of all the gases that can be carried and also that 4.3.3.3.2 has not been amended since it was introduced in 1981.
There was consensus that, as the relevant information is already contained in the transport documents and orange plates, then 4.3.3.3.2 could safely be deleted for tank vehicles and tank containers. However, there were reservations over the foldable panels used on tank wagons and that the RID standing working group should be consulted.
The conclusion for now is that, in RID, reference to MEGCs will be deleted from 4.3.3.3.2 and that it is the intention to also delete reference to tank-wagons, though this remains to be confirmed. For ADR, 4.3.3.3.2 is deleted.
TANK DESIGN AND CONSTRUCTION Russia proposed a clarification to the wording of special provision TE 14 in 6.8.4 which, it said, currently implies that thermal insulation must be in direct contact with the shell. Tank wagons for liquid tar, for instance, have a space between the shell and the thermal insulation to allow air to circulate and goods of UN 3257, which is covered by TE 14, can be carried in tanks designed for liquid tar. The Working Group agreed with Russia’s point and adopted revised wording for the second sentence of TE 14: The thermal insulation directly in contact with the shell and/or components of the heating system shall have an ignition temperature at least 50 °C higher than the maximum temperature for which the tank was designed.
Russia also sought clarification of 6.8.2.1.10 and 6.8.2.1.11 on the methods of heat treatment for welded shells which, in particular prohibit the use of water-quenched steel, and supported its paper with reference to various standards. There was agreement within the Working Group that, in principle, waterquenched steels could be used if they could demonstrate sufficient ductility and weldability, for which the 0.85 ration between Re/Rm specified in the first sentence of 6.8.2.1.11 is essential (though it is not clear where this figure originated). The Working Group suggested, and its suggestion was agreed in plenary, that this was an issue that should go up the chain to the UN Sub-committee of Experts on the Transport of Dangerous Goods.
Russia also proposed permitting the use of aluminium alloys within the scope of special provision TC6, for vessels carrying UN 2031 concentrated nitric acid, on the grounds that it would align with the use of such materials for packagings referred to in 6.1.4.2.1. As suitable aluminium alloys are now available that have better mechanical properties than pure aluminium, it was felt there was no reason to deny the proposal. As a result, TC6 is amended to read: The wall thickness of tanks made of aluminium not less than 99% pure or aluminium alloy need not exceed 15 mm even where calculation in accordance with 6.8.2.1.17 gives a higher value.
INSPECTION AND CERTIFICATION The UK provided a report of the 13th session of the informal working group on the inspection and certification of tanks (the ‘London Working Group’), which had taken place in midDecember 2019 under the chairmanship of Steve Gillingham (UK).
There were three main topics discussed. Firstly, the group reviewed the proposed text on the reciprocal recognition of inspection bodies, reaffirming that, once approved by a competent authority, an inspection body may be recognised by another competent authority.
Secondly, proposals would require competent authorities to base the approval of inspection bodies on accreditation to EN ISO/ IEC 17020:2012, or on an equivalent national standard approved by the RID Committee of Experts or WP 15. Austria offered a process by which such systems could be checked, based on the method used to recognise classification societies in 1.15 of ADN, which was supported in principle.
The most contentious item relates to the proposed entry into service verification (EISV). As proposed, the competent authority of the country of first registration, or of the country to where the tank is transferred, may require an EISV by an inspection body. This could be on the basis of suspicions arising from an administrative check of the tank documentation, or of market intelligence from tank inspections or surveillance activities.
It was acknowledged that an EISV may not be suitable for some sectors, such as tank containers and tank wagons, but it was noted that the EISV is not a mandatory requirement. It was decided to defer further discussions until the next session of the Joint Meeting.
The Joint Meeting instructed the Working Group on Tanks to deal with three tasks: - Development of a survey for the contracting parties to clarify the direction of the work
concerning the application of national systems for the approval of inspection bodies. - How to proceed with EISV, on the basis of a consensus that the intention is for the
EISV to be a market surveillance or market intelligence led activity which takes place on an occasional rather than on a systematic basis. - To advise on the use of Type C accredited inspection bodies. The London Working Group was due to meet again on 16 to 18 December and will report back to the Joint Meeting at its March 2021 session.
OTHER TANK MATTERS The International Union of Wagon Keepers (UIP) and the International Union of Railways (UIC) sought clarification on the use of tanks after the deadline specified for their next test or inspection, following up on a paper from Poland at the Joint Meeting in spring 2019. In the view of the two organisations, 4.3.2.3.7 is not currently clear as to whether tanks may be filled or offered for carriage in the one-month and three-month periods specified, or merely allowed to finish their carriage or be moved to allow dangerous goods to be properly recycled or disposed of. This paragraph does not apply
A NUMBER OF TECHNICAL QUESTIONS WERE to intermediate inspections, which are dealt with in 6.8.2.4.3; this has a three-month grace period, although again this has led to different interpretations.
Most experts who spoke were of the opinion that 6.8.2.4.3 is written in such a way that the tank could be used without restriction, including filling, in the three months after expiry of the due date of the intermediate inspection. After all, merely passing the due date does not suddenly render a tank unsafe. However, it was noted that this unrestricted use was compromised by the obligations of the filler in 1.4.3.3(b). It was thought that this grace period could be removed from 6.8.2.4.3, or alternatively that additional wording could be inserted to clarify the situation. A common understanding and interpretation are vital but no consensus could be reached. UIP was invited to submit a new document.
On similar lines, France asked what kind of inspection should be carried out if the period of three months after the date specified for the intermediate inspection has lapsed. Its paper noted that, at the September 2019 Joint Meeting, a new 6.7.2.19.6.2 had been adopted to deal with this issue for tanks covered by Chapter 6.7 and France felt that similar clarification is needed for tanks covered by Chapter 6.8.
Most experts who spoke were of the opinion that the normal due inspection should be performed and, from experience over many years, saw no additional safety benefits in performing more stringent inspections. Consequential cleaning for the periodic test would lead to high costs and pressure on the environment and additional hydraulic pressure tests could introduce moisture into the tank, thus leading to corrosion. The UIP representative offered to take those comments onboard and submit a fresh proposal at a future session.
France also asked the Working Group for its opinion on the interpretation of EN 13530, which applies to the design and construction of double-wall tanks, where the interspace is under vacuum to provide insulation, and 9.7.6 of ADR, which deals with the rear protection of vehicles and specifies a clearance of at least 100 mm between the rear wall of the tank and the rear of the bumper. Is this 100 mm measured from the rear wall of the outer casing or the rear wall of the inner shell?
Several experts confirmed the interpretation that if ‘tank’ is described, the distance to be considered is that of the rear of the bumper to the rear outermost parts of the insulation system. However, it was pointed out that this provision goes back to the original ADR and that at that time, ‘shell’ and ‘tank’ were not so strictly defined, which allowed some room for interpretation. It is also not clear what “the rear of the bumper” refers to, and this should be clarified. A document on this issue has also been submitted to WP 15. »
Another paper from France asked for direction on the use of the table in 6.8.2.6.1, which contains the list of standards to be used for issuing type approvals. Some difficulties may arise where standards for equipment are introduced into the table when an existing tank type approval does not refer to such standards. I this case, does the type approval need to be updated or renewed? Perhaps some clarification in RID/ADR would be useful to avoid misinterpretation.
The Working Group said that general type approvals must be checked each time a new version of RID/ADR is published, as described in 6.8.2.3.3. If a new, mandatory standard is referenced, this must be taken into account as well. However, it was stressed that if a new version of such an equipment standard were published and there is no end date in column 5, it would not be necessary to update the type approval of the tank. The opinion was also expressed that the text of 6.8.2.3.3 would not allow the type approval to be updated, as the type approval should be withdrawn by the competent authority or the body designated by that authority, resulting in a new type approval. It was felt that the holder should be given the choice of whether to update or withdraw the type approval. The discussion should be continued, taking into account 6.8.2.3.3 and the equivalent provision in 1.8.7.
Russia questioned the consistency – or lack In 6.8.2.1.13, the wording specifies that the pressure on which the shell thickness calculation is based shall not be less than the calculation pressure, leaving it open to use a higher pressure, which could lead to a higher wall thickness. It was agreed that this also requires amendment but the document will be kept on the table for consideration at a future session.
Russia similarly sought amendment of 6.8.2.2.2, which deals with external stress values for the internal stop-valve and its seating, saying that the current wording hampers understanding. It should be amended to clarify that the stresses referred to are those that occur in emergencies. The Working Group did not completely agree, feeling that the provision addresses nonemergency incidents as well as in-transit collisions. In the end, the Working Group felt that the current wording has proven itself over many decades and does not need changing.
The Netherlands queried the interpretation of 6.8.3.2.3 in ADR, dealing with the fitment of automatic closing valves on the filling lines of road tankers. Recent expansion in the transport of LNG, and with the likelihood that hydrogen will also become a more common lading, leaves the risk that flammable gases (the vapour phase of cryogenic liquids) may not be protected by such valves when carried in tank containers. Its paper came with three questions: is the opening in the vapour phase of LNG tanks to be regarded as a filling/ discharge opening, shall this opening close automatically in the event of fire, and shall this opening be equipped with three closures in series?
There was general consensus that the position of the Netherlands could be confirmed, although it could not be guaranteed that all tanks in service have the automatic closing safety function. It was said that the texts of 6.8.3.2 and the standards for tanks for refrigerated liquefied gases were not easy
of – between the different provisions for the calculation of minimum shell thickness in various paragraphs in Chapter 6.8 and, in particular, 6.8.2.1.16 and 6.8.2.1.13. For instance, 6.8.2.1.16 refers to the limitations concerning permissible stress (Sigma) being based on test pressure, whereas 6.8.2.1.17 is clear that Sigma applies to both test and calculation pressure. It was felt that these should be the same but no consensus could be reached on how to address the matter, as it requires further careful consideration.
INCREASING USE OF TANK CONTAINERS FOR LNG
to understand and that the text of 6.8.3.2 may benefit from a review. The Netherlands was invited to submit an official document for a future session.
The UK proposed that the manufacturer’s serial number should be stamped on the tank shell to ensure identification if the tank plate is lost or removed. It was pointed out that this is also a requirement in EN 12972:2018, which will be mandatory from 1 January 2022. The Working Group did not feel it necessary to include this in the regulations themselves; nor should it apply retrospectively to existing tanks.
The second part of this report on the Joint Meeting of RID/ADR/ADN Experts in next month’s HCB will cover the report of the Working Group of Standards and discussion of pending and new proposals for amendment to the regulations.
